I’ve spent most of my working life in “old school” companies, where business was booming without “engagement” or “fans.” So I’m skeptical of any social media hacks that promise the keys to the kingdom.

But last month, a few guys on our team at IWT showed me that social media can be useful.

On two different campaigns, they crushed their opt-in goals by 49% and 57% through shares and retweets.

They did this using the same secret that companies like Dropbox, LinkedIn, and Internet Explorer used to get millions of users without any advertising.

It’s called a viral loop. It’s a way to make it easy for people to sign up for your product and tell others about it. You can also use a viral loop to grow your email list and get people who wouldn’t hear of you otherwise to sign up.

Today I’m going to walk you through everything you need to know.

The viral loop: A party everyone wants to get into

First off, what exactly is a viral loop?

Let me explain with an analogy…

Pretend you want to throw a massive party that everyone will be talking about for months to come. The catch is that you can only invite one person.

I don’t know about you, but I would call up a friend who knows a lot of people in town and tell him to invite others. And to let those others know they’re free to get the word out, too.

So just from one invite, I can get 10 (possibly more) people to the party.

A single invite can turn into 10 party guests.

If everyone keeps spreading the word, the party will get really big, really fast.

If new guests get the word out, 30 more could show up. This all started with one invite.

That’s how a viral loop works. You invite one group of people, they invite the next group, and so on.

What’s the best way to get the next group of people to show up? Make it worthwhile.

For a party, it could be free food, drinks, or even just saying a lot of cool people will be there.

When someone sends a friend an invitation, it’s like them saying, “Hey, I like this. You should check it out, too.” It’s a recommendation from a trusted source, so people are more likely to sign up.

Let me show you the steps to creating your own viral loop, along with a real example.

Step 1: Find an idea that spreads like a wildfire

As a kid, my older brother’s friends loved to scare the bejeezus out of me.

One day they told me that if you chant “Bloody Mary” in front of a mirror, a bloody corpse of a woman will appear. And that sometimes she reaches out and strangles the people who call her. In fact, they said, they knew people it had happened to.

Then they start chanting in front of a mirror. And I bolted out of the house (glad that I wore my brown corduroy pants that day).

Over the years, I discovered this is a popular urban legend. But even with this in mind, I still get goosebumps when I see a mirror and think about it.

Why do I remember an idea like that after all these years? And how does it still manage to give me the heebie-jeebies?

Let’s go into the six principles that make the Bloody Mary idea sticky. Then I’ll show you how to use them in business.

Principle #1: SimplicityThe idea of standing in front of a mirror is nothing special. They’re household items. We use them everyday. (I give myself pep talks with them all the time. “Come on Choi, you gotta come up with a better sentence than that!”)

Principle #2: UnexpectednessThe unexpected turn with the Bloody Mary idea is that someone other than yourself will appear in the mirror by chanting her name. That’s spooky! I just got the willies from writing that.

Principle #3: ConcretenessThe legend, as my brother’s friends told me, was that, “a bloody corpse of a woman” will appear. And she sometimes reaches out and strangles people through the mirror. Those details paint a concrete picture in my head. That’s why I still remember it.

Principle #4: CredibilityDon’t give me that look — I was young. Anything the older boys told me I accepted as the truth. They were credible sources.

Principle #5: EmotionsI don’t know about you, but the idea of a bloody woman in the mirror reaching out and strangling me makes me feel one emotion: fear. If you can make people feel something, they won’t forget it.

Principle #6: StoriesOnce my brother’s friends started telling me the story of chanting “Bloody Mary,” I couldn’t stop listening. I had to hear what happened next, even though I didn’t want to. And I had to know what happened to the people who chanted. People love a good story. Good marketers know this, and that’s why they use them all the time in their promotions.

The 6 principles in action

At GrowthLab, we used these 6 principles to successfully promote a recent mini-course.

During our research, we found that many people want to own an online business. But 90% of them have never tried to start one because they “couldn’t think of a good business idea.”

So we ran a free class on “How to find your online business idea in 5 days or less.”

The subhead on the landing page was: “Go from ‘no idea’ to profitable idea with this FREE course — even if you’re busy and don’t know where to start.”

It hit each of the sticky idea principles:

Simple – “Finding an online business idea” is easy to remember

Unexpectedness – This is the hardest part of getting started for most. So promising an idea in 5 days is an unexpected twist

Create a “how to” guide: World record powerlifter and trainer, Jordan Syatt did a guide on “How to master the deadlift.” Java Jenius has “how to” guides on everything from fixing various brewing machines to making the perfect cup of coffee.

Step 2: Create a landing page and promote it

Whatever sticky idea you choose, create a landing page to get the word out. Here’s what we did for our 5-day course on finding a business idea:

Our mini-course hit all 6 principles.

To promote the mini-course, we tweeted and posted on Facebook with a link to the page:

Encouraging people to share will drive your viral loop.

If you haven’t been using social media like this, start doing it for your next webinar.

These social sharing buttons are what will introduce your material to new people and get them to sign up for your email list.

Step 3: Turn your “thank you” page into a viral loop machine

Have you ever signed up for an email list through a website, hit the opt-in button, and been redirected to another page? We call those “thank you” pages.

Most people overlook this critical piece and leave a generic confirmation message on there. But you can turn your page into an engine that drives your viral loop across the web.

First let me explain how we did it with our 5-day course from above.

As usual, we sent everyone to a “thank you” page after they entered their email and signed up.

On the page, we embedded the tweet and Facebook post I showed you before. And we asked readers to share or retweet.

Here’s what it looked like:

The “thank you” page where people can help you spread the word

So on your “thank you” page, embed the tweet (and screenshot the FB post) and write a line or two asking them to share it.

The copy doesn’t need to be fancy. You can follow our example above and write, “Retweet on Twitter…Hit the retweet button, or click here to retweet.”

Or, “Share on Facebook…Click the share button above, or click here to share.”

Now it’s time to hang on for the ride.

Step 4: Get your biggest fans to spread the word

You’ve got the foundation down. Next you want to get your fans to help you out.

Send your email list a message announcing your sticky idea. Here’s an example of what we sent out:

Of course your list will be the #1 source of sign-ups.

But when you mention the free course, since it’s a sticky idea, something else happens. Your readers will want to spread the word to people who are interested in the same thing.

When they see the social sharing buttons on the thank you page, they’ll think, “I don’t want my friends to miss this!”

And with the option to share right there, they’re more likely to take action.

You can see the results for yourself: 474 retweets and 124 shares on Facebook.

Tons of engagement and new subscribers

For a company that didn’t focus on social media until recently, that’s a lot. It also got tons of engagement and built a lot of buzz.

The friends of your biggest fans who see these retweets and shares will go directly to your landing page for the webinar or mini-course. And a good number of them will sign up, which means fresh names for your email list.

At GrowthLab, we set benchmarks for campaigns like this. On two recent ones, as I mentioned, we crushed our opt-in goals by 49% and 57%, just by using the exact steps we used.